rocksdb/db/blob/blob_contents.cc
Levi Tamasi 7818560194 Add a dedicated cache entry role for blobs (#10601)
Summary:
The patch adds a dedicated cache entry role for blob values and switches
to a registered deleter so that blobs show up as a separate bucket
(as opposed to "Misc") in the cache occupancy statistics, e.g.

```
Block cache entry stats(count,size,portion): DataBlock(133515,531.73 MB,13.6866%) BlobValue(1824855,3.10 GB,81.7071%) Misc(1,0.00 KB,0%)
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10601

Test Plan: Ran `make check` and tested the cache occupancy statistics using `db_bench`.

Reviewed By: riversand963

Differential Revision: D39107915

Pulled By: ltamasi

fbshipit-source-id: 8446c3b190a41a144030df73f318eeda4398c125
2022-08-29 16:11:59 -07:00

89 lines
2.4 KiB
C++

// Copyright (c) Meta Platforms, Inc. and affiliates.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#include "db/blob/blob_contents.h"
#include <cassert>
#include "cache/cache_entry_roles.h"
#include "cache/cache_helpers.h"
#include "port/malloc.h"
namespace ROCKSDB_NAMESPACE {
std::unique_ptr<BlobContents> BlobContents::Create(
CacheAllocationPtr&& allocation, size_t size) {
return std::unique_ptr<BlobContents>(
new BlobContents(std::move(allocation), size));
}
size_t BlobContents::ApproximateMemoryUsage() const {
size_t usage = 0;
if (allocation_) {
MemoryAllocator* const allocator = allocation_.get_deleter().allocator;
if (allocator) {
usage += allocator->UsableSize(allocation_.get(), data_.size());
} else {
#ifdef ROCKSDB_MALLOC_USABLE_SIZE
usage += malloc_usable_size(allocation_.get());
#else
usage += data_.size();
#endif
}
}
#ifdef ROCKSDB_MALLOC_USABLE_SIZE
usage += malloc_usable_size(const_cast<BlobContents*>(this));
#else
usage += sizeof(*this);
#endif
return usage;
}
size_t BlobContents::SizeCallback(void* obj) {
assert(obj);
return static_cast<const BlobContents*>(obj)->size();
}
Status BlobContents::SaveToCallback(void* from_obj, size_t from_offset,
size_t length, void* out) {
assert(from_obj);
const BlobContents* buf = static_cast<const BlobContents*>(from_obj);
assert(buf->size() >= from_offset + length);
memcpy(out, buf->data().data() + from_offset, length);
return Status::OK();
}
Cache::CacheItemHelper* BlobContents::GetCacheItemHelper() {
static Cache::CacheItemHelper cache_helper(
&SizeCallback, &SaveToCallback,
GetCacheEntryDeleterForRole<BlobContents, CacheEntryRole::kBlobValue>());
return &cache_helper;
}
Status BlobContents::CreateCallback(const void* buf, size_t size,
void** out_obj, size_t* charge) {
CacheAllocationPtr allocation(new char[size]);
memcpy(allocation.get(), buf, size);
std::unique_ptr<BlobContents> obj = Create(std::move(allocation), size);
BlobContents* const contents = obj.release();
*out_obj = contents;
*charge = contents->ApproximateMemoryUsage();
return Status::OK();
}
} // namespace ROCKSDB_NAMESPACE